Problems & Puzzles: Puzzles

Puzzle 1143 Palindromic Prime Pyramid step 3 On set 13, 2023, G.L. Honaker, Jr. sent the following nice puzzle: Palindromic Prime Pyramid 2 3002003 3303002003033 9303303002003033039 7609303303002003033039067 3007609303303002003033039067003 9003007609303303002003033039067003009 3819003007609303303002003033039067003009183 7113819003007609303303002003033039067003009183117 7407113819003007609303303002003033039067003009183117047 1207407113819003007609303303002003033039067003009183117047021 9701207407113819003007609303303002003033039067003009183117047021079 7019701207407113819003007609303303002003033039067003009183117047021079107 … Above are the first 13 rows of a palindromic prime prime pyramid (step size 3) that can eventually end with a 559-digit prime and a total of 94 rows. Calculation shows that the maximum height (number of rows) of such type of pyramid is around 193. See the 94th row here: https://www.utm.edu/staff/caldwell/supplements/ In the same reference we may read this "Starting with 2, there should be one of height around 193 (ending with a 1153 digit prime)". See https://www.utm.edu/staff/caldwell/preprints/JRM_prime_pyramids.pdf   Q. Find a palindromic prime pyramid of step size 3 with a height (number of rows) greater than 94.

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During the week from 16-23 Set 2023, contributions came from Michael Branicky, J-M Rebert, Giorgos Kalogeropoulos, Oscar Volpatti, Gennady Gusev, Alessandro Casini, Simon Cavegn.

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Here is a table with the results received

Contributor	File	Height or rows
Michael	here	120
Rebert	here	105
Giorgos	here	111
Oscar	here	116
Gennady	here	109
Alessandro	here	116
Simon	here	124